The present invention relates to programmable elements within integrated circuits, and more specifically to an amorphous silicon programmable element.
Anti-fuse devices are commonly used in one-time programmable elements within integrated circuit chips. The anti-fuse material forms a high resistance barrier until programmed. Programming is typically performed by applying a voltage across the element.
Known programmable elements typically employ aluminum as the primary conducting material. Thus, the degree of miniaturization that can be achieved with such elements is limited. Such designs cannot be reliably fabricated using less than one square micron of area. Also, such elements are necessarily complex in design. See, for example, U.S. Pat. No. 4,914,055 to Gordon et al., and U.S. Pat. No. 4,823,181 to Mohsen et al.
Therefore, it would be desirable to provide a programmable element which requires significantly less area to manufacture and which can be easily manufactured at the same time that other devices on the chip are being fabricated.